I wanted a lightweight Gridfinity base for my tstak drawers. I took the outline of the bottom and added the gridfinity base generated by the Gridfinity Openscad model. It should also work with craftsman versastack drawers, but I don't have one to test. I've split the base over 4 pieces, just glue them together after printing.
The author remixed this model.
I generated the base and added the outline so it would fit the drawer